{"entity": "publication", "iuid": "20f75d48bfab45b8b24b08f46cdccb30", "timestamp": "2026-09-23T21:35:43.474Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/20f75d48bfab45b8b24b08f46cdccb30.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/20f75d48bfab45b8b24b08f46cdccb30"}}, "title": "High Amounts of SARS-CoV-2 Precede Sickness Among Asymptomatic Health Care Workers.", "authors": [{"family": "Dillner", "given": "Joakim", "initials": "J"}, {"family": "Elfstr\u00f6m", "given": "K Miriam", "initials": "KM"}, {"family": "Blomqvist", "given": "Jonas", "initials": "J"}, {"family": "Engstrand", "given": "Lars", "initials": "L"}, {"family": "Uhl\u00e9n", "given": "Mathias", "initials": "M"}, {"family": "Eklund", "given": "Carina", "initials": "C"}, {"family": "Boulund", "given": "Fredrik", "initials": "F"}, {"family": "Lagheden", "given": "Camilla", "initials": "C"}, {"family": "Hamsten", "given": "Marica", "initials": "M"}, {"family": "Nordqvist-Kleppe", "given": "Sara", "initials": "S"}, {"family": "Seifert", "given": "Maike", "initials": "M"}, {"family": "Hellstr\u00f6m", "given": "Cecilia", "initials": "C"}, {"family": "Olofsson", "given": "Jennie", "initials": "J"}, {"family": "Andersson", "given": "Eni", "initials": "E"}, {"family": "Falk", "given": "August Jernbom", "initials": "AJ"}, {"family": "Bergstr\u00f6m", "given": "Sofia", "initials": "S"}, {"family": "Hultin", "given": "Emilie", "initials": "E"}, {"family": "Pin", "given": "Elisa", "initials": "E"}, {"family": "Pimenoff", "given": "Ville N", "initials": "VN"}, {"family": "Hassan", "given": "Sadaf", "initials": "S"}, {"family": "M\u00e5nberg", "given": "Anna", "initials": "A"}, {"family": "Nilsson", "given": "Peter", "initials": "P"}, {"family": "Hedhammar", "given": "My", "initials": "M"}, {"family": "Hober", "given": "Sophia", "initials": "S", "orcid": "0000-0003-0605-8417", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/4a1bdfd8500c4dbea343132bc0d8e44c.json"}}, {"family": "Mattsson", "given": "Johan", "initials": "J"}, {"family": "Arroyo M\u00fchr", "given": "Laila Sara", "initials": "LS"}, {"family": "Lundgren", "given": "Kalle Conneryd", "initials": "KC"}], "type": "journal article", "published": "2021-07-02", "journal": {"title": "J. Infect. Dis.", "issn": "1537-6613", "volume": "224", "issue": "1", "pages": "14-20", "issn-l": "0022-1899"}, "abstract": "Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity among asymptomatic subjects reflects past or future disease may be difficult to ascertain.\n\nWe tested 9449 employees at Karolinska University Hospital, Stockholm, Sweden for SARS-CoV-2 RNA and antibodies, linked the results to sick leave records, and determined associations with past or future sick leave using multinomial logistic regression.\n\nSubjects with high amounts of SARS-CoV-2 virus, indicated by polymerase chain reaction (PCR) cycle threshold (Ct) value, had the highest risk for sick leave in the 2 weeks after testing (odds ratio [OR], 11.97; 95% confidence interval [CI], 6.29-22.80) whereas subjects with low amounts of virus had the highest risk for sick leave in the 3 weeks before testing (OR, 6.31; 95% CI, 4.38-9.08). Only 2.5% of employees were SARS-CoV-2 positive while 10.5% were positive by serology and 1.2% were positive in both tests. Serology-positive subjects were not at excess risk for future sick leave (OR, 1.06; 95% CI, .71-1.57).\n\nHigh amounts of SARS-CoV-2 virus, as determined using PCR Ct values, was associated with development of sickness in the next few weeks. Results support the concept that PCR Ct may be informative when testing for SARS-CoV-2. Clinical Trials Registration. NCT04411576.", "doi": "10.1093/infdis/jiab099", "pmid": "33580261", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC7928785"}, {"db": "pii", "key": "6134453"}, {"db": "ClinicalTrials.gov", "key": "NCT04411576"}], "notes": [], "created": "2026-09-23T12:17:16.392Z", "modified": "2026-09-23T12:17:16.411Z"}